<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var allChars = 'abcdefghjkmnpqrstxyz23456789';
    var s = '';
    for (var i = 0;i<8;i = i+1){
        var r = Math.floor(Math.random()*28);
        console.log(r);
        s = s + allChars[r];
    }

    console.log(s.toUpperCase());


</script>

</body>
</html>